• Builder delaying refund amount after cancellation, non delivery of unit beyond timelines

I had booked an apartment in under construction apartment (newly announced then) in February 2016. The assurance of delivery was in Jan 2019+grace period 6 months. Project is still at its infancy in construction & will take as an estimate 2 years more (2023). Meanwhile builder in Jan 2019 changed project name, changed dimensions of the construction as well. This change of name was informed to us through a formal letter and acceptance was taken on new dimensions (increased area) and additional amount to be paid at the delivery. Since then as well, there is just a marginal progress in construction. I have paid INR 20 lacs to the builder through cheque in 2016. I have all receipts etc. I had taken this apartment under subvention scheme, hence builder was paying pre-EMIs on loan amount, total loan disbursed is INR 6 lacs. Due to delay in delivery and time lapse, my financial priorities have changed & I have requested cancellation (through a form) to builder in August 2020, and they accepted the same, its been almost 7 month now. The builder needs to 1) close the loan by prepaying INR 6 lacs 2) return INR 20 lacs and 3) pay pending pre-EMIs of past 7 months. I have written emails to the entire management team of builder's organisation including the Managing Director regarding this issue & helping me out. The builder has returned INR 2 lacs so far to me. For pending refund, they are consistently extending timelines & asking for more time. I cant wait more as I am in need of the amount, hence have filed a case in RERA. RERA authorities have sent enquiry on 4 March 2021 to builder with a timeline to respond till 25 March 2021 (N O T I C E ISSUED UNDER RULE 30(2)(a) as below)
"This complaint bearing No.# has been filed by the complainant Sri/Smt. $$ under S.31 of RERA Act alleging that you have violated the provisions of the said act and thereby he is seeking Get refund of INR 20,96,640/- from Builder + get home loan closure + closure of pending PRE-EMIs + compensation due to non-delivery, loss of time/effort + 5 yrs interest on down-payment amount. The complaint copy is annexed herewith calling upon you to say on these allegations. If you want to plead guilty then file a memo to that effect either through online or by submitting physical copy in the office. If you do not plead guilty of these allegations; you are hereby call upon to file written objections either through online or by submitting physical copy in the office within office hours on or before 25.03.2021.If not, matter will be heard on merits with the available evidence by fixing a date for hearing through Skype."

want help from you:
1) What are the next steps in this RERA case and how should I be prepared (documents etc)
2) In the notice RERA authorities have asked me to send the softcopy of all documents supporting the complaint to the builder...should i be doing this
3) Is it advisable to simultaneously approach other forums like consumer court, if yes, pl guide which ones & how